1. Field of the Invention
The present invention relates to information retrieval. More specifically, the invention relates to tools for traversing hypertext data.
2. Background Information
The development of computerized information resources such as the Internet and various on-line services, such as CompuServe.TM., America On-Line.TM., Prodigy.TM. and other services has lead to a proliferation of electronically-available information. This electronic information is increasingly displacing more conventional means of information transmission, such as newspapers, magazines and even television.
The largest information resource in existence today is the Internet. The Internet is a group of client and server computers linked one to another and each having a unique identifier, DNS (distributed network server), assigned by the Internet authority in Cambridge, Mass. and Geneva, Switzerland. In order for information to be found on the Internet every file is given a specific address by which it may be located. To access the Internet a user employs what is called a browser. Currently the most popular browser is Netscape Navigator.TM. browser developed by Netscape Communications Corporation of Mountain View, Calif. A wide array of browsers is available for just about every platform. The browser's job is twofold. First, given a pointer to a piece of information on the net it has to be able to access the information or operate in some way based on the contents of that pointer. Second, if the document/file (hereinafter file) is encoded the browser has to translate that to a suitable format for display to the user. The display may include multimedia effects, e.g. sound and animation.
The most popular encoding of Internet files communicated between client and server is the HTML (hypertext markup language). The WWW (World Wide Web) or simply the "Web" includes all the servers adhering to this standard. Each page loaded from the Internet is a single file encoded in HTML. HTML describes the structure of a file. The structure of the file includes title, paragraphs, images and any pointers to other files.
The pointer to a specific site is called an URL (Uniform Resource Locator). The URL provides a universal, consistent method for finding and accessing information for a Web browser. The URL comprises a file type, a server I.D. (DNS), one or more directories and subdirectories, and a file name. URLs are also used as part of a hypertext link within a file to another file. These URLs then provide the browser with a way to navigate the Web. URLs contain information about a file: including file type (FTP, Gopher, HTTP), the Internet server on which the file is located (WWW.NCSA.UIUC.EDU, or FDP.APPLE.COM, or Net Com 16.Net.Com, and so on), the directory of the file, and the file name.
In order to speed the process of finding relevant information on the Internet several servers on the Internet provide an index to the Internet and a search engine. These information indexers such as Yahoo.TM., Excite.TM., Lycos.TM., Inktomi.TM., and Alta Vista.TM. perform two valuable functions. First, using their own Internet links, they continually search the Internet and index all files on the Internet into subject categories and store this index on their own database. The information indexers also allow a client to connect to their server and enter a search query. In response the information indexer provides a list of all files on the web that meet the search criteria. Therefore, the information indexer such as Yahoo.TM. not only updates and maintains a topical index for all files on the web, but also makes that index searchable by a client. It should be noted that the information that is retrieved from Yahoo.TM. contains only a general topic identifier and the file location on the Internet for that specific topic.
It would indeed be a cumbersome process for the client seeking specific information if the indexes that were retrieved from Yahoo.TM. only told the searcher where to look. If this were the case, the considerable task remaining to the client would be to manually enter the network address, URL, of each file and the go through the process of retrieving that file. To overcome this problem, the search result retrieved by Yahoo.TM. is encoded in HTML as a hot-link which makes every "footnote" an active rather than a passive reference. These hot-links appear to the user in the browser window as bold face text which is easily distinguished from the other text based information in the file. A hot-link comprises a text description and a corresponding URL. When the user selects a hot-link the browser detects that selection and outputs the URL on the Internet to retrieve the file corresponding to that URL and display it to the user. Therefore, by merely selecting with a mouse a specific footnote in a file encoded in a markup language, a client is immediately given access to the remote web server that contains the specific file referred to in the footnote.
With a markup language such as HTML (hypertext markup language) both amateurs and professionals become authors and the footnotes on the printed page become the hypertext of the electronic page. What was a passive reference now becomes an accessible link to a related file. A markup language describes the structure of a file including headings, paragraphs, images and what are called hot-links. A hot-link displays at the user level as text or graphic and is processed for communication purposes as an URL. It is these hot-links which provide the interactive footnotes described above.
Even with the indexing provided by Yahoo.TM., Lycos.TM., Excite.TM., Inktomi.TM., Alta Vista.TM., etc., the process of finding the exact topic is still extremely time consuming and can involve visiting literally hundreds of Web Sites. Typically, a user will retrieve a file from an information indexer and will not only look at the files retrieved by selecting the indexers hot-links, but will also select other hot-links in the retrieved documents. This process of starting a search that begins with an initial hot-link and following a search trail that leads to successive files each increasingly displaced from the starting point is known as a drill-down. The problem with current browsers is that when a user has drilled-down through many levels of sites, the only way to return to the original HTML file is to hit the browser's back key which moves the user up one level at a time through the original search tree back to level "1." Only then can the user access other hot-links retrieved in the original search.
What is needed is a more efficient way to conduct a search.